Under the direction of Dr. John D. Altman, the mission of Core H, the Emory CFAR Immunology Core Laboratory (ICL), is to provide the Emory community with the highest quality assessments of immunological function necessary for the study of the pathogenesis, treatment, and prevention of immunodeficiency virus infections in humans and non-human primates. The ICL will achieve this mission through the following Specific Aims: 1. Develop and perform optimized, standardized, and validated assays of cellular immune function in vaccinated subjects, in HIV-infected humans, and in SIV-infected non-human primates (NHP); 2. Create a repository of cryopreserved PBMC from naive (off-study) monkeys from the Yerkes Primate Research Center, thereby providing CFAR investigators with access to esse'ntial negative control samples for assay development and validation. 3. Achieve economies of scale through the provision of immunological reagent resources shared by multiple independent laboratories; 4. Maintain a CFAR Flow Cytometry Core, for the purpose of providing members of the Emory CFAR, and the larger AIDS research community, with the highest quality flow cytometry data and cell sorting services available, including handling of biohazardous samples; 5. Promote immunological assay education and training opportunities for CFAR investigators, the AIDS research community in Atlanta, and national and international AIDS investigators. Through these Aims, the ICL will enable all Emory CFAR investigators to take advantage of innovative and powerful modern approaches to quantitative analysis of innate and acquired humoral and cell-mediated immunity that have been developed by individual Emory investigators and scientists elsewhere. Accurate characterization of cell-mediated immune responses is essential for guiding preclinical vaccine development, for determining possible correlates of vaccine efficacy in preclinical and clinical trials, and for better understanding AIDS pathogenesis.